A generic methodology based on Six-Sigma techniques for designing and manufacturing consumer products for functionality

This research presents a systematic procedure to generate design and manufacturing guidelines to ensure product functionality. We critically examine product design and manufacture literature with a view to understanding why consumer products of daily use, supposed to be functional, routinely fail to provide the intended function to users' satisfaction. The traditional definitions of functionality, and the methods and tools used in representing function in a product need to be extended. There are manufacturing considerations that have a direct impact on making the product. Two sets of specific checklists, one for evaluating product functionality and the other consisting of design and manufacture guidelines, were developed. Information necessary for developing these checklists was obtained through sources such as users, manufacturers, published literature, and design handbooks. To evaluate the effectiveness of the checklists, it was hypothesised that all product functionality scores, considered collectively, would not differ between users and designers. To illustrate the utility of the procedure, a case study has been presented.